Antistatic fiber blend



ABSTRACT OF THE DISCLOSURE A blend of hydrophobic synthetic fibershaving improved antistatic properties and improved processabilitythrough textile machines consisting essentially of a major proportioncomprising from about 55% to about 90% of the fibers in the blend havingapplied thereto a durable friction-reducing antistatic agent and a minorproportion comprising from about 10% to about 45% of the fibers in theblend having applied thereto a friction-increasing agent.

This invention relates to synthetic fibers which have improvedantistatic properties and improved processability through textilemachines. More particularly, these two desirable characteristic ofsynthetic fibers, are achieved through the use of the present inventionwherein a major proportion of the fibers in a blend of such fibers haveincorporated therein a durable antistatic agent while the remainingminor proportion of the fibers in such blend have incorporated therein afriction-increasing agent, which, preferably, is a nondurable antistaticagent.

The difiiculties arising from the generation and accumulation of staticelectricity in synthetic fibers, due to their hydrophobic nature, arewell known. These difiiculties arise during the use of end products madefrom such fibers, and, to an even greater extent, during textileprocessing and manufacturing operations to make such end products.

In order to overcome these difficulties, it has been proposed to applydurable antistatic agents to these fibers or to a minor proportion ofsuch fibers in a blend with a major proportion of untreated fibers.

Unfortunately, such techniques have resulted in greatly increaseddifficulties in processing the yarns through the textile machinerynecessary to convert staple fibers into threads (as compared withnaturally antistatic hydrophilic fibers such as cotton and wool).However, these durable antistatic agents do produce textile fabricswhich have a softer hand than would be achieved with the same fiberswhich are untreated.

In accordance with the present invention, it has been found that greatlyimproved textile processability of these hydrophobic fibers can beachieved while producing satisfactory antistatic properties by blendinga major proportion of fibers having incorporated therein a durableantistatic agent with a minor proportion of fibers having incorporatedtherein a friction-increasing agent, which preferably is a nondurableantistatic agent.

The need for the friction-increasing agent became apparent when wediscovered that the cause of poor processability of the synthetic fiberstreated with a durable antistatic agent resulted from a lowering of thefrictional char.- acteristics of such yarns.

However, it was also discovered that the textile fabrics made from yarnsprocessed in accordance with our invention had a relatively harsh handunless the friction-increasing agent was nondurable (i.e., could bereadily removed from the fabrics by scouring, washing, etc.).Accordingly, our invention therefore contemplates that thefriction-increasing agent preferably be a nondurable agent when it isdesired to produce fabrics having a relatively soft hand.

Also, since the tendency of hydrophobic fibers} to build up staticcharges is much greater during the conditions of textile processing,particularly those encountered in picking and carding, then it is duringconditions of consumer use of the textile products, it is important thatthe fibers have a higher degree of antistatic properties during textileprocessing. Accordingly, the friction-increasing agent should alsopossess antistatic properties so as to provide the higher degree ofprotection necessary during the textile processing operations.

Illustrative of hydrophobicsynthetic fiberswhich are .of particularinterest in the practice of our invention are those fibers prepared fromvinyl polymers, for example, acrylic fibers, polypropylene fibers,polyvinyl chloride fibers, and the like, and fibers prepared frompolymers of polyesters, polyacetals, polyurethanes, and polyamides.

Any of the many durable antistatic agents commonly known may be used onthe major proportion of the hydrophobic fibers. Illustrative of thesedurable antistatic agents are those formed from polyethylene glycol,such as the condensation products of polyethylene glycol diamine andpolyethylene glycol dihalide of which Aston 108, Aston '123, and AstonLT sold by Onyx Chemical Corporation, and Stanax and Stanax 1166 sold byStandard Chemical Products, Inc., are commercially available examples.These compounds may be cured with polyepoxides after application to thefibers to produce a durable antistatic finish therein and thereon bysuch processes as taught in Anthes US. Patent 2,982,751, issued May 2,1961, which also lists other compounds of this type useful in thepractice of our invention. Similarly, these compounds may be cured withdihalides. Also useful are other compounds sold for use as durableantistatic agents such as Zerostat P (polyoxyethylene diepoxide,cross-linked with a diamine) sold by Ciba Chemical and Dye Co. andAerotex Antistatic No. 6 (polyoxyethylene amine, cross-linked withcyanuric chloride) sold by American Cyanamid Company.

These durable antistatic agents may be applied to the fibers at anystage of processing in any of the conventional Ways. It is importantonly that the durable antistatic agent be applied to the fibers prior toblending them' Name Description Sold By Permolite Solubilized alkydresin. Arkansas Co. Inc. Aerotex Resin 700..- Urea-formaldehydeAigerican Cyanamid condensate. o. Aerotex Resin 803... Modifiedurea-formalde- Do.

hyde condensate. Iberantislip Solubilized protein A. Harrison & 00.,Inc. Kolina Adhesive..- Modified vinylpyrroli- Antara Chemical Co.

done resin. Atlas G-750 Sodium sorbital borate Atlas Chemical Industry,Inc. Atlas (Ii-3300...".-. Alkylamine alkane Do.

sulfonate. Non-slip Finish Water-soluble modified Apex Chemical Co.,

No. 22. resin. nc. Beratex No. 510 Modified all-rylarylsul- BerkshireColor &

. ion e. Chemical Co. Arogum Protein blend A181 Chemical Product I r o.Larnol 60-98 Polyvinyl alcohol Borden Chemical Co. Estralok A H2Osoluble-polym- Crown Chemical Corp.

' erized resin ester. Melltone SCR Polyoxyethylene ester Do.

composition. Lubritone SA Emulsified lubricants.-- Chas. S. Tanner Co.Conco Non-slip Viscid water-soluble Continental Chemical Special A & B.resin. 00. Lureen Special"..- Fatty based derivative George A. GautstonC0.

iv/bonding agents. Krinkle Finish-.-" Emulsified fatty esters.. GrestooDyes &

Chemical, Inc. Syton DS Colloidal silica Mmsanto Chemical 0.Lenoscroop600 Modified fatty ester"-.. Lenox Chemical Co.

emulsion. Cachalot -2l Oleyl alcohol M. Michel & C0. Atco Bindtex 11...-Water-soluble resin Metro-Atlantic, Inc. Prosotex CR Blended organicaoids Quaker Chemical Corp. Standatln 92 Water-soluble thermo- StandardChemical plastic resin. Product Inc.

In the preferred embodiments of our invention, the friction-increasingagent also serves as an antistatic which is nondurable (i.e., easilyremoved from the fibers in the finished product by washing or scouring).Illustrative of these non-durable friction-increasing antistatic agentsare the following:.

o. Lekrostat B, GV--- Heterocyclic amine Dextfir Chemical Corp.

Lekrostat C Fatty annne salts o. Aquazine 88 Fatty hydrazmlum MoretexChemical chloride Products Inc. OrcoLAntlstatic Cationic compound..Organic Chemical Corp.

83 Parastat S Polyoxyethylene alkyl- Trylon Chemical amine. Corp.Borne-stat.-,t Polyalkylaryl sulfo- Borne Chermcal Co.

nate. Dowfax 2A1 Dodecyldiphenyloxide Dow Chemical Co.

disulfonic aced. Emkastat K Sulfonated aliphatic Emkay Chemical Colcompound. Seyco Stat-96 Blend of fatty esters Seydel-Wodley & C0.

. and polyoxyethylene fatty derivatives. Zelac NE Alcolhol phosphate DuPont.

composition. Cirrasol GM Polyglycol ester Arnold, Hofiman & Co. LubrolWX. Fatty-alcohol ethylene Do.

oxide condensate. Carbowax... Polyethylene glycol.. UmglncCarbrde Chem-1c 0. Y Sorbinox L-20 Polyoxyethylene sorbi- Trylon Chemical Corp.

tan monolaurate. Paralube 20 -.do Do. Textiline 3645 Nonionic esters andSonneborn Chemical &

hydrocarbons. Refining Corp. Sonostat-GO Nonionic derivative-.." DoSyn-stat 400 Polyethylene glycol Syn-Chemical Corp.

derivatives. Syn-stat BH...... Complex phosphated Do. alcohol.

- Name Descriptiom Sold By Syn-stat D- Polyethylene glycol Syn-ChemicalCorp.

derivatives. Stantex 810 Blend of fatty and Standard Chemical syntheticlubricants. Products. Elosol SG Ethyleneoxide conden- Do.

sa e. Elosol V Amphoteric compound. Sandoz, Inc. LubrofinPolyoxyethylene csters. Richmond Oil, Soap &

Chemical Co. Nopcostat AS-40..- Fatty amide Nopco Chemical Co. Nopcostat2152K... Fatty ester Do. Nopcostat LV-40 Fattty amide and fatty Do.

os er. Vimset Fatty acid ethylene- MctroAtlautic, Inc.

oxide condensate. Lenostat Plus Blend of nonionic Lenox Chemical Co.

esters. Lenoscroop 125.-- Modified fatty ester Do.

emulsion. Conditionol Blend of humectant Maker Color & Chemagentsw/amine conical Co.

densates.

Conditionol W. Mixture of sulfonated Bryant Chemical Co. 0115, resinsand Y These friction-increasing agents may be applied to the fibers atany stage of processing in any of the conventional ways. It is importantonly that they be applied to the fibers prior to blending them withother fibers which have been treated with a durable antistatic agent,which blending occurs prior to formation of the fibers into threads.Preferably the friction increasing agent is incorporated on the fibersso treated in an amount sufiicient to increase the frictionalcharacteristics of the blend of fibers to a level comparable to thosefibers for which the textile processing equipment was designed, as inthe cotton system, the woolen system, and the worsted system. Usuallythis can be achieved with the use of an amount of friction-increasingagent between about 0.25% and 1.0% based on the weight of fibers sotreated. It is important that the fibers treated with thefriction-increasing agent constitute a minor proportion, preferably.from 10% to of the fibers in the blend, particularly when such agent isnondurable.

The following examples will serve to illustrate a particular embodimentof our invention and some of the advantages thereof. In each of theseexamples, the fibers used were acrylic fibers of a copolymer ofacrylonitrile and methylmethacrylate prepared by wet-spinning from anaqueous sodium thiocyanate solution thereof.

Example Crimped acrylic fibers were padded in a trough with aformulation containing Aston 108 (a condensation product of polyethyleneglycol diamine and polyethylene glycol dihalide), cut into 2 staple, wetopened, dried at about C. for about nine minutes, and then cured with apolyepoxide as taught in Anthes US Patent 2,982,- 751, issued May 2,1961, for about nine minutes at about 114 C. to form a productidentified as Fiber A which contained about 0.6% durable antistaticagent based on weight of fiber.

Other acrylic fibers were padded with Nopco LV-40 finish (a mixture offatty amides and fatty esters), crimped, cut into 2" staple; wet opened,and dried at about 60 C. for'about nine minutes to form a productidentified as Fiber B which containedvabout 0.5% nondurablefriction-increasing antistatic agent based on weight of fiber.

A blend was prepared containing Fiber A and 35% Fiber B by introducingthe dry fibers in the proper proportions into a wet opener and thenpassingthe mixture through a dry opener. The resulting blend was readilyprocessable through thecotton system (which includes picker, card, drawframe, roving frame, and spinning frame) without .diffi'culty. oven andknitted products from threads so made from this blend of fibersexhibited a very soft hand afterwashing and scouring toaremove 'at allon textile equipment. These fibers were not blended with any otherfibers.

antistatic rating after ten machine washes was fair to good or better.It will also be noted that where the fraction of the fibers treated withthe durable antistatic agent was 45% or less, the processability ontextile equipment ranged from very poor down through not processable.

Example 3 In a similar manner, a lot of Fiber A, prepared as in Example1, was processed on the cotton system after being properly opened.Numerous interruptions of operations for cleaning were required due tooverloading of the feed roll prior to the beater in picking the fiber.The lap was poor, 'very, soft, and uneven. Carding required use of afancy and loading of the drum was excessive. Sliver from the card, onpassing through the trumpet to the can, caused excess finish to build upin the trumpet. Drawing and roving steps were troubled with roll lappingand build-up of finish on the rolls. Spinning was troubled with finishbuilding up on the rolls also, all causing inferior yarns to be formed.

Example 4 Other fibers were prepared using other permanent antistaticagents as indicated in the following table. In this table it will beseen that fibers treated with the permanent antistatic agent ranged frompoor to not processable the nondurable finish while still exhibitingsatisfactory t li q g b a ti tatic resistance to the accumulation ofstatic charges. 5 iq w-cessa u y a I A Q Exam le 2 Q Stanax 0.25 goorun0.50 ery poo Good In a manner similar tott-hat of Example 1, otherblends 0.75 Not proces bl were prepared in which. a maj r. pr porti n. fthe fibers mm 1166 12 V553jjj D were treated with a durable antistaticagent and a minor 1.00 Not processablo. proportion of the fibers weretreated with a friction- 108 8:2 gf,- 82 55 increasing agent. Thedurable antistatic agent and the 0.75 Not mcessabla. Ifriction-increasing agent were applied to their respective i 2 ggjjjjlots of fibers utilizing the general procedures of Example Aston 1230.25 Poor-very poor Fair. 1. These blends, detailed in the followingtable, all pro-. 15 i i g g pl'ows' duced fiber blends having thecharacteristics indicated A t A 0.75 Notp in the table. It will be notedthat in all cases where the percent of fibers treated with the durableantistatic agent was equal to or greater than 55%, the pro-cessabilityonDurable antistatic agent Percent D-A Percent D-A Friction-increasingPercent F-I Percent F-l Processabilit o A t (D-A) on fiber treated fiberagent (F-I) on fiber treated fiber textile 611111135 1613; at t ei i n iliig in blend in blend washes Stanax 0.25 80 N0pc'ostat LV40 0.5Failugood 0 50 65 do 0.7 35 Good.

75 0.7 75 Do. 0.75 65 0.5 35 Do. I 0 f 0.5 75 Poor.

L 55 0. 5 45 Good-fair. 2.0 0. 5 75 Evidence of static. Stanax 1150 0.2565 600%0 0.5 80 0.25 20 1.0 43 0.5 55 V good 0.5 20 Good. Aston 108 iFairagood 75 0. 5 25 Excellent-good. 0. 75 65 Myr 45 0. 25 Good. 1 0 25Nopcostat LV 0. 7 75 55 d0 0.7 1.5 35 0.7 Aston 123 0- 5 30 0. 5 20Fair-good.

M t- 0.4 35 Good. 1 0 1 (852 8.: :3(5) good-excellent. 6 2; a N m... 65i Aerotex antistatic No. 1 005 a 0.5 20 Good F 0.75 65 .do 0.25 35 do...Gi tid 1. 5 65 .-d0 0. 5 35 Fair-good textile equipment was good or verygood, and that the Example 5 In a similar manner, a lot of Fiber B wasopened and subsequently converted to fabric with no textile processingdifiiculty. Picking, carding, drawing, etc. were all performed at acommercially acceptable level of performance. These fabrics, so formed,before and after being subjected to the normal predyeing scour or afterdyeing had a very harsh scroopy handle characteristic of most man-madefibers. Also, after scouring or dyeing, these fibers had no antistaticprotection at all.

Example 6 Fiber C was prepared in the same manner as Fiber A (seeExample 1) except that Aston 123 are used instead of Aston 108 and theproducted contained 1.75% durable antistatic agent based on weight offiber.

A- blend was prepared containing 33% Fiber C and 67% untreated acrylicfibers by introducing the dry fibers in the proper proportions into awet opener and then passing the mixture through a dry opener. Theresulting blend could not be processed through the cotton system underconditions approaching normal. During picking, the fibers exhibitedstatic accumulation by adhering to the hopper walls. Also, the fibersbunched up under and behind the feed roll prior to the beater. The lapfrom the picker was uneven and contained many fused fibers.

-Even when lighter loads of fiber were fed, successful operations werenot obtained.

We claim: 1. A blend of hydrophobic synthetic fibers having improvedantistatic properties and improved processability through textilemachines consisting essentially of 2. A blend of hydrophobic syntheticfibers having improved antistatic properties and improved processabilitythrough textile machines consisting essentially of (a) a majorproportion comprising from about 55% to about 90% of the fibers in theblend having applied thereto a durable friction-reducing antistaticagent, and (b) a minor proportion comprising from about 10% to about 45%of the fibers in the blend having applied thereto a readily removablefriction-increasing antistatic agent. 3. The product of claim 2 whereinthe fibers of said major proportion have applied thereto 0.25% to 2.0%of -18 durable friction-reducing antistatic agent on weight of fibersinsaid major proportion and wherein the fibers of said minor proportion.have applied thereto 0.25% to 1.0% of readily removablefriction-increasing antistatic agent on weight of .fibers in said minorproportion.

4. The product of claim 2 wherein said hydrophobic synthetic fibers areall acrylic fibers.

5. The product of claim 2 wherein said durablefrictionreducing'antistatic agent comprises a product of crosslinking alinear polymer formed by the condensation of polyethylene glycol diamineand polyethylene glycol dihalide.

References Cited UNITED STATES PATENTS 2,832,697 ,4/1958 Walles 177138.8X 2,897,170 7/1959 Gruber ll7--139.5 2,982,751 5/1961 Anthes 117-1395 X3,008,215 11/1961 Pitts ll7139.5 X 3,019,132 1/1962 Gabler l17139.5 X3,108,011 10/1963 Frotscher 8115.5 X 3,167,448 1/1965 Hirshfeld1l7-139.5 X 3,245,905 4/1966 White et a1 117-l38.8

WILLIAM D. MARTIN, Primary Examiner. R. HUSACK, Assistant Examiner.

